Adapter base for electric lamp

ABSTRACT

An adapter screw-base is attached to a lamp of the type having cup-shaped ferrule terminals, by means of an adapter disc positioned over the ferrule terminals and against the lamp envelope and held in place by fastening means attached to the outer ends of the ferrule terminals. A screw-base is positioned with its skirt surrounding the adapter disc and attached thereto by interlocking indentations. Wires provide electrical connections between the screw-base and ferrule terminals.

United States Patent 1191 1 1 fifiwfi Cardwell, Jr. $1113 17, 1973 [54]ADAPTER BASE FOR ELECTRIC LAMP 3,622,947 11/1971 Griffin 339/146inventor: J G. Cardweu, J Kirtland 2,791,713 5/1957 Dean 313/318 X OhmPrimary Examiner-Ronald L. Wibert [73] Assignee: General ElectricCompany, Assistant Examiner-Paul A. Sacher Schenectady, NY.Attorney-Norman C. Fulmer et a1. 22 F'] d: A 1 197 1 l 57 ABSTRACT 1Appl' "(L589 An adapter screw-base is attached to a lamp of the typehaving cup-shaped ferrule terminals, by means of an [52] US. Cl.313/318, 339/146 adapter disc positioned over the ferrule terminals and[51] Int. Cl. H01j 5/48 against the lamp envelope and held in place byfasten- [58] Field of Search 313/318; 174/50, ing means attached to theouter ends of the ferrule ter- 174/52; 339/146 minals. A screw-base ispositioned with its skirt surrounding the adapter disc and attachedthereto by in- [56] References Cited terlocking indentations. Wiresprovide electrical con- UNITED STATES PATENTS nections between thescrew-base and ferrule terminals. 773,805 11/1904 Miller 339/ 146 10Claims, 4 Drawing Figures Patented July 17, 1973 3,746,906

lnventor: John G. CardweLL, Jr".

' His A t torneg 1 ADAPTER BASE FOR ELECTRIC LAMP BACKGROUND OF THEINVENTION The invention is in the field of electric lamps provided withbases, and is particularly directed to an adapter base attachmentassembly for the type of lamp provided with terminal posts such ascup-shaped ferrule terminals.

Certain types of lamps, such as built-in reflector lamps, are oftenprovided with terminal posts, usually in the form of cup-shaped ferruleterminals embedded into the glass or quartz envelope material andextending rearwardly thereof. Electrical connections to the ferruleterminals are made in several different ways, such as by soldering orwelding flexible wires to the terminals, or soldering or weldingscrew-terminals to the ferrule terminals, or by clamping a socket to theterminals. It is sometimes desirable to attach a screw-base to such alamp. U.S. Pat. No. 2,098,080 to Daniel Wright discloses a screw-baseadapter into which lamp prongs, extending from ferrule terminals, areinserted. U.S. Pats. No. 2,262,629 to Daniel Wright and No. 3,515,930 toLaverne Walsh and Gerald Keimer each disclose a screw-base adapterpositioned with its skirt fitting around a specially shaped shoulder onthe lamp envelope and secured thereto by cement or interlockingindentations.

SUMMARY OF THE INVENTION Objects of the invention are to provide animproved adapter base assembly for lamps of the type having terminalposts such as cup-shaped ferrule terminals, and to provide such a baseassembly which is tightly and permanently secured to the lamp withoutrequiring any specially shaped shoulder on the lamp envelope forattachment of the base.

The invention, briefly and in a preferred embodiment, provides anadapter-base for a lamp of the type having terminal posts such ascup-shaped ferrule terminals extending from the lamp envelope,comprising an adapter member positioned over the terminal posts andagainst the lamp envelope, fastening means attached to the outer ends ofthe terminal posts for holding the adapter member in place, a basemember attached to the, adapter member, and electrical connectorsconnected between the base member and the terminal posts.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an exploded side view of apreferred embodiment of the invention, showing the base member detachedfrom the rest of the assembly;

FIG. 2 is a view taken on the line 2-2 of FIG. 1, looking downwardly onthe lamp and adapter member assembly;

FIG. 3 is a side view of FIG. 1, looking toward the right-hand sidethereof, with the base member attached to the rest of the assembly; and

FIG. 4 is a perspective view of the adapter member.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawing shows a reflectorlamp 11, such as type PAR 36, provided with a shaped glass bulb portion12 having a parabolic aluminized reflective inner surface, a glass coverplate 13 being sealed thereto at the rim thereof. A pair of cup-shapedferrule terminals l6, l7

are sealed at the open edges thereof to the glass bulb 12 so that theclosed ends of the ferrules extend rear-- wardly from the bulb, asshown. Openings are provided in the bulb 12 axially of the ferrules l6,17. The ferrules 16 and 17 are respectively provided with rearwardlyextending nipples l8 and 19, into which a pair of lead wires arerespectively positioned and soldered, the other ends of the lead wiresbeing connected to a filament 23 within the lamp 11. A pair of flatbosses 26, 27 rise from the curved contour of the bulb 12 in thevicinity of the ferrules 16 and 17, as shown, to provide level surfaceareas into which the open ends of the ferrules 16 and 17 are sealed. Asealed-off exhaust tubulation 28 extends rearwardly of the bulb 12,between the ferrules 16 and 17.

In accordance with the invention, an adapter member in the form of aceramic disc 31 is provided with a pair of openings 32 and 33therethrough, so as to fit over and around the ferrule terminals 16 and17, and a slot 34 extends between the openings 32 and 33, so that theceramic disc 31 will clear the sealed-off exhaust tubulation 28. Theadapter member 31 is positioned over the ferrules 16 and 17 and againstthe back surface of the glass envelope bulb 12, as shown in FIGS. 1 and2. A pair of fastener members 36, 37 are respectively attached to thenipples l8 and 19 of the ferrule terminals 16 and 17, so as to hold theceramic disc 31 in place, i.e., wedged between the fastener members 36,37 and the rear portion of the bulb 12 as partly defined by the raisedbosses 26 and 27. The fastener members36 and 37 may comprise washer-likedevices such as so-called speed nuts" which are pressed over the nipplesl8 and 19 and remain in position due to spring-wedging tension of tabspressing against the nipples. If desired, the speed nuts may be solderedto the nipples 18 and 19. Alternatively, the fastener members 36 and 37may comprise metal washers positioned over and around the nipples 18 and19, and soldered thereto. A pair oflead wires 38 and 39 are respectivelysoldered to the fastening members 36 and 37, or to the nipples l8 and19.

A screw-base member 41 comprises a cylindrical threaded portion 42, aninsulated endcontact disc 43 at an end thereof, and a'cylindrical skirtportion 44 at the otherend thereof, which may be electrically insu latedfrom the cylindrical threaded portion, as shown. The base 41 ispositioned with the skirt 44 around the adapter disc 31, cut-outportions 44 being provided at the edge of the skirt portion 44 so as toclear the raised bosses 26 and Y27, so that the circumferential edge ofthe skirt 44rests against the rear of the bulb I2; Indentations 45 areprovided'in the skirt 44 to lock it into recesses 46 provided in theceramic adapter 31. The lead wire 38 extends through an opening 47 inthe side wall of the screw-threaded portion 42, and is soldered to thethreaded portion 42 as indicated at numeral 48. The lead wire 39 extendsthrough an opening in an end of the base and through the contact disc43, and is soldered thereto as indicated at numeral 49.

By providing an adapter member 31 fitted over the terminal posts 16, 17and against the rear of the bulb 12, and holding it in place by fastenermeans attached to the connector posts 16' and 17, and attaching the basemember to the adapter member 31, as described above, the base 41 isrigidly attached to the lamp 1] without the necessity of providing aspecial shoulder on the bulb 12 for attachment of the base 41.

While a preferred embodiment of the invention has been shown anddescribed, various other embodiments and modifications thereof willbecome apparent to persons skilled in the art, and will fall within thescope of invention as defined in the following claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A base assembly for a lamp of the type having terminal postsextending substantially mutually parallel from a surface of the lamp,comprising an adapter member shaped and positioned to fit over saidterminal posts and against said surface of the lamp, fastening meansattached to said terminal posts in a position to hold said adaptermember in place, and a base member attached to said adapter member andconnected electrically to said terminal posts.

2. A base assembly as claimed in claim 1, in which said fastening meanscomprises washer-like devices respectively positioned around saidterminal posts and soldered thereto, said washer-like devices bearingagainst a surface of said adapter member so as to hold the adaptermember in position against said surface of the lamp.

3. A base assembly as claimed in claim 1, in which said fastening meanscomprises washer-like devices of the speed nut type respectivelypositioned around said terminal posts and held in place by means ofintegral inwardly extending tabs pressing against said terminal posts,said devices bearing against a surface of said adapter member so as tohold the adapter member in position against said surface of the lamp.

4. A base assembly as claimed in claim 1, in which said adapter memberis disc-shaped and provided with one or more openings therethrough intowhich said terminal posts extend.

5. A base assembly as claimed in claim 4, in which the thickness of saidadapter member is less than the lengths of said terminal posts extendingfrom said surface of the lamp.

6. A base assembly as claimed in claim 4, in which said base member iscylindrically shaped and provided with an open-end skirt portion shapedand positioned to closely surround the periphery of said disc-shapedadapter member.

7. A base assembly as claimed in claim 6, in which said skirt portion ofthe base member and said periphery of the disc-shaped adapter member areprovided with interlocking indentations for fastening said base memberto said adapter member.

8. A base assembly as claimed in claim 1, in which said terminal postscomprise cup-shaped ferrules sealed at the open ends thereof into saidsurface of the lamp, each of said ferrules being provided with anoutwardly extending nipple at the closed outer end thereof, saidfastening means respectively surrounding and being attached to saidnipples of the terminal posts.

9. A base assembly as claimed in claim 1, in which said adapter memberis disc-shaped and provided with one or more openings therethrough intowhich said terminal posts extend, the thickness of said adapter memberbeing less than the lengths of said terminal posts extending from saidsurface of the lamp, said base member being cylindrically shaped andprovided with an open-end skirt portion shaped and positioned to closelysurround the periphery of said disc-shaped adapter member, said skirtportion of the base member and said periphery of the disc-shaped adaptermember being provided with interlocking indentations for fastening saidbase member to said adapter member.

10. A base assembly as claimed in claim 8, in which said base member isa screw-base provided with a cylindrical threaded portion.

1. A base assembly for a lamp of the type having terminal postsextending substantially mutually parallel from a Surface of the lamp,comprising an adapter member shaped and positioned to fit over saidterminal posts and against said surface of the lamp, fastening meansattached to said terminal posts in a position to hold said adaptermember in place, and a base member attached to said adapter member andconnected electrically to said terminal posts.
 2. A base assembly asclaimed in claim 1, in which said fastening means comprises washer-likedevices respectively positioned around said terminal posts and solderedthereto, said washer-like devices bearing against a surface of saidadapter member so as to hold the adapter member in position against saidsurface of the lamp.
 3. A base assembly as claimed in claim 1, in whichsaid fastening means comprises washer-like devices of the ''''speednut'''' type respectively positioned around said terminal posts and heldin place by means of integral inwardly extending tabs pressing againstsaid terminal posts, said devices bearing against a surface of saidadapter member so as to hold the adapter member in position against saidsurface of the lamp.
 4. A base assembly as claimed in claim 1, in whichsaid adapter member is disc-shaped and provided with one or moreopenings therethrough into which said terminal posts extend.
 5. A baseassembly as claimed in claim 4, in which the thickness of said adaptermember is less than the lengths of said terminal posts extending fromsaid surface of the lamp.
 6. A base assembly as claimed in claim 4, inwhich said base member is cylindrically shaped and provided with anopen-end skirt portion shaped and positioned to closely surround theperiphery of said disc-shaped adapter member.
 7. A base assembly asclaimed in claim 6, in which said skirt portion of the base member andsaid periphery of the disc-shaped adapter member are provided withinterlocking indentations for fastening said base member to said adaptermember.
 8. A base assembly as claimed in claim 1, in which said terminalposts comprise cup-shaped ferrules sealed at the open ends thereof intosaid surface of the lamp, each of said ferrules being provided with anoutwardly extending nipple at the closed outer end thereof, saidfastening means respectively surrounding and being attached to saidnipples of the terminal posts.
 9. A base assembly as claimed in claim 1,in which said adapter member is disc-shaped and provided with one ormore openings therethrough into which said terminal posts extend, thethickness of said adapter member being less than the lengths of saidterminal posts extending from said surface of the lamp, said base memberbeing cylindrically shaped and provided with an open-end skirt portionshaped and positioned to closely surround the periphery of saiddisc-shaped adapter member, said skirt portion of the base member andsaid periphery of the disc-shaped adapter member being provided withinterlocking indentations for fastening said base member to said adaptermember.
 10. A base assembly as claimed in claim 8, in which said basemember is a screw-base provided with a cylindrical threaded portion.